Include names of the people involved in 406 IPC

I will be pressing for action under Sec. 406 IPC. However, the opp. parties (my in-laws) are senior citizens, whether any leniency would be given by the court if I file this case u/s 406. The conspiracy was hatched by my (1) in-laws, (2) two brother-in-law and (3) my sister-in-law. All are residing at my own residence (free of cost) from 2003 to 2007 and thereafter they taken away our property documents and kept with them illegally. Now, If I want to go ahead to file case u/s 406, do I have to include my brother-in-laws/sister-in-law as a party? (they have all signed as witness) . Where to file this case (in the magistrate court or in the police station). Please advise.